Associating a ListView with a collection of objects

How can you use a ListView to show the user a collection of objects, and to manage those objects?

From stackoverflow Asmor

• For the purpose of argument, here's our design goal: We've got a "monster" object, and that "monster" will have several "powers." The user interacts with the powers via a ListView item.

  First, we create a Power object. Give the object the following method:

  public ListViewItem makeKey()
  {
      return new ListViewItem(name);
  }
  

  where name is the name of the power, and a string. This ListViewItem will serve as a key, allowing us to identify and retrieve this power later.

  Next, we need to add somewhere in the Monster object to keep track of all these powers.

  public Dictionary<ListViewItem,Power> powers;
  

  So now we need a way to add powers to the monster.

  public void addPower(Power newPower) {
      ListViewItem key = newPower.makeKey();
      monster.powers.add(key, newPower);
  }
  

  Ok, almost done! Now we've got a dictionary of ListViewItems which are tied to the monster's powers. Just grab the keys from that dictionary and stick them in a ListView:

  foreach (ListViewItem key in powers.Keys)
      powerList.Items.Add(key);
  

  Where powerList is the ListView we're adding the ListViewItems to.

  Alright, so we've got the ListViewItems in the ListView! Now, how do we interact with those? Make a button and then a function something like this:

  private void powerRemoveButton_Click(object sender, EventArgs e)
  {
      if (powerList.SelectedIndices.Count > 0)
      {
          int n = powerList.SelectedIndices[0];
          ListViewItem key = powerList.Items[n];
          monster.powers.Remove(key);
          powerList.Items.Remove(key);
      }
      else
      {
          MessageBox.Show("No power selected.");
      }
  }
  

  And that's that. I hope you've found this helpful. I'm not sure if this was an intentional aspect of their design, but ListViews and Dictionaries blend together so amazingly well when you use a ListViewItem as a key that it's a joy!

  Josh : Seriously... you posted that much of an answer to your own question almost simultaneously.

  Asmor : I thought it was a handy tip, and it was suggested that I post and answer my own question if I wanted to share a tip. I typed the answer beforehand and pasted it after I submitted the question.
  From Asmor